drivers/net/xen-netback/interface.c

   1 /*
   2  * Network-device interface management.
   3  *
   4  * Copyright (c) 2004-2005, Keir Fraser
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License version 2
   8  * as published by the Free Software Foundation; or, when distributed
   9  * separately from the Linux kernel or incorporated into other
  10  * software packages, subject to the following license:
  11  *
  12  * Permission is hereby granted, free of charge, to any person obtaining a copy
  13  * of this source file (the "Software"), to deal in the Software without
  14  * restriction, including without limitation the rights to use, copy, modify,
  15  * merge, publish, distribute, sublicense, and/or sell copies of the Software,
  16  * and to permit persons to whom the Software is furnished to do so, subject to
  17  * the following conditions:
  18  *
  19  * The above copyright notice and this permission notice shall be included in
  20  * all copies or substantial portions of the Software.
  21  *
  22  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  23  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  25  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  26  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  27  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  28  * IN THE SOFTWARE.
  29  */
  30
  31 #include "common.h"
  32
  33 #include <linux/kthread.h>
  34 #include <linux/ethtool.h>
  35 #include <linux/rtnetlink.h>
  36 #include <linux/if_vlan.h>
  37 #include <linux/vmalloc.h>
  38
  39 #include <xen/events.h>
  40 #include <asm/xen/hypercall.h>
  41 #include <xen/balloon.h>
  42
  43 #define XENVIF_QUEUE_LENGTH 32
  44 #define XENVIF_NAPI_WEIGHT  64
  45
  46 /* Number of bytes allowed on the internal guest Rx queue. */
  47 #define XENVIF_RX_QUEUE_BYTES (XEN_NETIF_RX_RING_SIZE/2 * PAGE_SIZE)
  48
  49 /* This function is used to set SKBTX_DEV_ZEROCOPY as well as
  50  * increasing the inflight counter. We need to increase the inflight
  51  * counter because core driver calls into xenvif_zerocopy_callback
  52  * which calls xenvif_skb_zerocopy_complete.
  53  */
  54 void xenvif_skb_zerocopy_prepare(struct xenvif_queue *queue,
  55                                  struct sk_buff *skb)
  56 {
  57         skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
  58         atomic_inc(&queue->inflight_packets);
  59 }
  60
  61 void xenvif_skb_zerocopy_complete(struct xenvif_queue *queue)
  62 {
  63         atomic_dec(&queue->inflight_packets);
  64 }
  65
  66 int xenvif_schedulable(struct xenvif *vif)
  67 {
  68         return netif_running(vif->dev) &&
  69                 test_bit(VIF_STATUS_CONNECTED, &vif->status) &&
  70                 !vif->disabled;
  71 }
  72
  73 static irqreturn_t xenvif_tx_interrupt(int irq, void *dev_id)
  74 {
  75         struct xenvif_queue *queue = dev_id;
  76
  77         if (RING_HAS_UNCONSUMED_REQUESTS(&queue->tx))
  78                 napi_schedule(&queue->napi);
  79
  80         return IRQ_HANDLED;
  81 }
  82
  83 int xenvif_poll(struct napi_struct *napi, int budget)
  84 {
  85         struct xenvif_queue *queue =
  86                 container_of(napi, struct xenvif_queue, napi);
  87         int work_done;
  88
  89         /* This vif is rogue, we pretend we've there is nothing to do
  90          * for this vif to deschedule it from NAPI. But this interface
  91          * will be turned off in thread context later.
  92          */
  93         if (unlikely(queue->vif->disabled)) {
  94                 napi_complete(napi);
  95                 return 0;
  96         }
  97
  98         work_done = xenvif_tx_action(queue, budget);
  99
 100         if (work_done < budget) {
 101                 napi_complete(napi);
 102                 xenvif_napi_schedule_or_enable_events(queue);
 103         }
 104
 105         return work_done;
 106 }
 107
 108 static irqreturn_t xenvif_rx_interrupt(int irq, void *dev_id)
 109 {
 110         struct xenvif_queue *queue = dev_id;
 111
 112         xenvif_kick_thread(queue);
 113
 114         return IRQ_HANDLED;
 115 }
 116
 117 irqreturn_t xenvif_interrupt(int irq, void *dev_id)
 118 {
 119         xenvif_tx_interrupt(irq, dev_id);
 120         xenvif_rx_interrupt(irq, dev_id);
 121
 122         return IRQ_HANDLED;
 123 }
 124
 125 int xenvif_queue_stopped(struct xenvif_queue *queue)
 126 {
 127         struct net_device *dev = queue->vif->dev;
 128         unsigned int id = queue->id;
 129         return netif_tx_queue_stopped(netdev_get_tx_queue(dev, id));
 130 }
 131
 132 void xenvif_wake_queue(struct xenvif_queue *queue)
 133 {
 134         struct net_device *dev = queue->vif->dev;
 135         unsigned int id = queue->id;
 136         netif_tx_wake_queue(netdev_get_tx_queue(dev, id));
 137 }
 138
 139 static int xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev)
 140 {
 141         struct xenvif *vif = netdev_priv(dev);
 142         struct xenvif_queue *queue = NULL;
 143         unsigned int num_queues = vif->num_queues;
 144         u16 index;
 145         struct xenvif_rx_cb *cb;
 146
 147         BUG_ON(skb->dev != dev);
 148
 149         /* Drop the packet if queues are not set up */
 150         if (num_queues < 1)
 151                 goto drop;
 152
 153         /* Obtain the queue to be used to transmit this packet */
 154         index = skb_get_queue_mapping(skb);
 155         if (index >= num_queues) {
 156                 pr_warn_ratelimited("Invalid queue %hu for packet on interface %s\n.",
 157                                     index, vif->dev->name);
 158                 index %= num_queues;
 159         }
 160         queue = &vif->queues[index];
 161
 162         /* Drop the packet if queue is not ready */
 163         if (queue->task == NULL ||
 164             queue->dealloc_task == NULL ||
 165             !xenvif_schedulable(vif))
 166                 goto drop;
 167
 168         cb = XENVIF_RX_CB(skb);
 169         cb->expires = jiffies + vif->drain_timeout;
 170
 171         xenvif_rx_queue_tail(queue, skb);
 172         xenvif_kick_thread(queue);
 173
 174         return NETDEV_TX_OK;
 175
 176  drop:
 177         vif->dev->stats.tx_dropped++;
 178         dev_kfree_skb(skb);
 179         return NETDEV_TX_OK;
 180 }
 181
 182 static struct net_device_stats *xenvif_get_stats(struct net_device *dev)
 183 {
 184         struct xenvif *vif = netdev_priv(dev);
 185         struct xenvif_queue *queue = NULL;
 186         unsigned int num_queues = vif->num_queues;
 187         unsigned long rx_bytes = 0;
 188         unsigned long rx_packets = 0;
 189         unsigned long tx_bytes = 0;
 190         unsigned long tx_packets = 0;
 191         unsigned int index;
 192
 193         if (vif->queues == NULL)
 194                 goto out;
 195
 196         /* Aggregate tx and rx stats from each queue */
 197         for (index = 0; index < num_queues; ++index) {
 198                 queue = &vif->queues[index];
 199                 rx_bytes += queue->stats.rx_bytes;
 200                 rx_packets += queue->stats.rx_packets;
 201                 tx_bytes += queue->stats.tx_bytes;
 202                 tx_packets += queue->stats.tx_packets;
 203         }
 204
 205 out:
 206         vif->dev->stats.rx_bytes = rx_bytes;
 207         vif->dev->stats.rx_packets = rx_packets;
 208         vif->dev->stats.tx_bytes = tx_bytes;
 209         vif->dev->stats.tx_packets = tx_packets;
 210
 211         return &vif->dev->stats;
 212 }
 213
 214 static void xenvif_up(struct xenvif *vif)
 215 {
 216         struct xenvif_queue *queue = NULL;
 217         unsigned int num_queues = vif->num_queues;
 218         unsigned int queue_index;
 219
 220         for (queue_index = 0; queue_index < num_queues; ++queue_index) {
 221                 queue = &vif->queues[queue_index];
 222                 napi_enable(&queue->napi);
 223                 enable_irq(queue->tx_irq);
 224                 if (queue->tx_irq != queue->rx_irq)
 225                         enable_irq(queue->rx_irq);
 226                 xenvif_napi_schedule_or_enable_events(queue);
 227         }
 228 }
 229
 230 static void xenvif_down(struct xenvif *vif)
 231 {
 232         struct xenvif_queue *queue = NULL;
 233         unsigned int num_queues = vif->num_queues;
 234         unsigned int queue_index;
 235
 236         for (queue_index = 0; queue_index < num_queues; ++queue_index) {
 237                 queue = &vif->queues[queue_index];
 238                 disable_irq(queue->tx_irq);
 239                 if (queue->tx_irq != queue->rx_irq)
 240                         disable_irq(queue->rx_irq);
 241                 napi_disable(&queue->napi);
 242                 del_timer_sync(&queue->credit_timeout);
 243         }
 244 }
 245
 246 static int xenvif_open(struct net_device *dev)
 247 {
 248         struct xenvif *vif = netdev_priv(dev);
 249         if (test_bit(VIF_STATUS_CONNECTED, &vif->status))
 250                 xenvif_up(vif);
 251         netif_tx_start_all_queues(dev);
 252         return 0;
 253 }
 254
 255 static int xenvif_close(struct net_device *dev)
 256 {
 257         struct xenvif *vif = netdev_priv(dev);
 258         if (test_bit(VIF_STATUS_CONNECTED, &vif->status))
 259                 xenvif_down(vif);
 260         netif_tx_stop_all_queues(dev);
 261         return 0;
 262 }
 263
 264 static int xenvif_change_mtu(struct net_device *dev, int mtu)
 265 {
 266         struct xenvif *vif = netdev_priv(dev);
 267         int max = vif->can_sg ? 65535 - VLAN_ETH_HLEN : ETH_DATA_LEN;
 268
 269         if (mtu > max)
 270                 return -EINVAL;
 271         dev->mtu = mtu;
 272         return 0;
 273 }
 274
 275 static netdev_features_t xenvif_fix_features(struct net_device *dev,
 276         netdev_features_t features)
 277 {
 278         struct xenvif *vif = netdev_priv(dev);
 279
 280         if (!vif->can_sg)
 281                 features &= ~NETIF_F_SG;
 282         if (~(vif->gso_mask | vif->gso_prefix_mask) & GSO_BIT(TCPV4))
 283                 features &= ~NETIF_F_TSO;
 284         if (~(vif->gso_mask | vif->gso_prefix_mask) & GSO_BIT(TCPV6))
 285                 features &= ~NETIF_F_TSO6;
 286         if (!vif->ip_csum)
 287                 features &= ~NETIF_F_IP_CSUM;
 288         if (!vif->ipv6_csum)
 289                 features &= ~NETIF_F_IPV6_CSUM;
 290
 291         return features;
 292 }
 293
 294 static const struct xenvif_stat {
 295         char name[ETH_GSTRING_LEN];
 296         u16 offset;
 297 } xenvif_stats[] = {
 298         {
 299                 "rx_gso_checksum_fixup",
 300                 offsetof(struct xenvif_stats, rx_gso_checksum_fixup)
 301         },
 302         /* If (sent != success + fail), there are probably packets never
 303          * freed up properly!
 304          */
 305         {
 306                 "tx_zerocopy_sent",
 307                 offsetof(struct xenvif_stats, tx_zerocopy_sent),
 308         },
 309         {
 310                 "tx_zerocopy_success",
 311                 offsetof(struct xenvif_stats, tx_zerocopy_success),
 312         },
 313         {
 314                 "tx_zerocopy_fail",
 315                 offsetof(struct xenvif_stats, tx_zerocopy_fail)
 316         },
 317         /* Number of packets exceeding MAX_SKB_FRAG slots. You should use
 318          * a guest with the same MAX_SKB_FRAG
 319          */
 320         {
 321                 "tx_frag_overflow",
 322                 offsetof(struct xenvif_stats, tx_frag_overflow)
 323         },
 324 };
 325
 326 static int xenvif_get_sset_count(struct net_device *dev, int string_set)
 327 {
 328         switch (string_set) {
 329         case ETH_SS_STATS:
 330                 return ARRAY_SIZE(xenvif_stats);
 331         default:
 332                 return -EINVAL;
 333         }
 334 }
 335
 336 static void xenvif_get_ethtool_stats(struct net_device *dev,
 337                                      struct ethtool_stats *stats, u64 * data)
 338 {
 339         struct xenvif *vif = netdev_priv(dev);
 340         unsigned int num_queues = vif->num_queues;
 341         int i;
 342         unsigned int queue_index;
 343         struct xenvif_stats *vif_stats;
 344
 345         for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++) {
 346                 unsigned long accum = 0;
 347                 for (queue_index = 0; queue_index < num_queues; ++queue_index) {
 348                         vif_stats = &vif->queues[queue_index].stats;
 349                         accum += *(unsigned long *)(vif_stats + xenvif_stats[i].offset);
 350                 }
 351                 data[i] = accum;
 352         }
 353 }
 354
 355 static void xenvif_get_strings(struct net_device *dev, u32 stringset, u8 * data)
 356 {
 357         int i;
 358
 359         switch (stringset) {
 360         case ETH_SS_STATS:
 361                 for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++)
 362                         memcpy(data + i * ETH_GSTRING_LEN,
 363                                xenvif_stats[i].name, ETH_GSTRING_LEN);
 364                 break;
 365         }
 366 }
 367
 368 static const struct ethtool_ops xenvif_ethtool_ops = {
 369         .get_link       = ethtool_op_get_link,
 370
 371         .get_sset_count = xenvif_get_sset_count,
 372         .get_ethtool_stats = xenvif_get_ethtool_stats,
 373         .get_strings = xenvif_get_strings,
 374 };
 375
 376 static const struct net_device_ops xenvif_netdev_ops = {
 377         .ndo_start_xmit = xenvif_start_xmit,
 378         .ndo_get_stats  = xenvif_get_stats,
 379         .ndo_open       = xenvif_open,
 380         .ndo_stop       = xenvif_close,
 381         .ndo_change_mtu = xenvif_change_mtu,
 382         .ndo_fix_features = xenvif_fix_features,
 383         .ndo_set_mac_address = eth_mac_addr,
 384         .ndo_validate_addr   = eth_validate_addr,
 385 };
 386
 387 struct xenvif *xenvif_alloc(struct device *parent, domid_t domid,
 388                             unsigned int handle)
 389 {
 390         int err;
 391         struct net_device *dev;
 392         struct xenvif *vif;
 393         char name[IFNAMSIZ] = {};
 394
 395         snprintf(name, IFNAMSIZ - 1, "vif%u.%u", domid, handle);
 396         /* Allocate a netdev with the max. supported number of queues.
 397          * When the guest selects the desired number, it will be updated
 398          * via netif_set_real_num_*_queues().
 399          */
 400         dev = alloc_netdev_mq(sizeof(struct xenvif), name, NET_NAME_UNKNOWN,
 401                               ether_setup, xenvif_max_queues);
 402         if (dev == NULL) {
 403                 pr_warn("Could not allocate netdev for %s\n", name);
 404                 return ERR_PTR(-ENOMEM);
 405         }
 406
 407         SET_NETDEV_DEV(dev, parent);
 408
 409         vif = netdev_priv(dev);
 410
 411         vif->domid  = domid;
 412         vif->handle = handle;
 413         vif->can_sg = 1;
 414         vif->ip_csum = 1;
 415         vif->dev = dev;
 416         vif->disabled = false;
 417         vif->drain_timeout = msecs_to_jiffies(rx_drain_timeout_msecs);
 418         vif->stall_timeout = msecs_to_jiffies(rx_stall_timeout_msecs);
 419
 420         /* Start out with no queues. */
 421         vif->queues = NULL;
 422         vif->num_queues = 0;
 423
 424         spin_lock_init(&vif->lock);
 425
 426         dev->netdev_ops = &xenvif_netdev_ops;
 427         dev->hw_features = NETIF_F_SG |
 428                 NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
 429                 NETIF_F_TSO | NETIF_F_TSO6;
 430         dev->features = dev->hw_features | NETIF_F_RXCSUM;
 431         dev->ethtool_ops = &xenvif_ethtool_ops;
 432
 433         dev->tx_queue_len = XENVIF_QUEUE_LENGTH;
 434
 435         /*
 436          * Initialise a dummy MAC address. We choose the numerically
 437          * largest non-broadcast address to prevent the address getting
 438          * stolen by an Ethernet bridge for STP purposes.
 439          * (FE:FF:FF:FF:FF:FF)
 440          */
 441         memset(dev->dev_addr, 0xFF, ETH_ALEN);
 442         dev->dev_addr[0] &= ~0x01;
 443
 444         netif_carrier_off(dev);
 445
 446         err = register_netdev(dev);
 447         if (err) {
 448                 netdev_warn(dev, "Could not register device: err=%d\n", err);
 449                 free_netdev(dev);
 450                 return ERR_PTR(err);
 451         }
 452
 453         netdev_dbg(dev, "Successfully created xenvif\n");
 454
 455         __module_get(THIS_MODULE);
 456
 457         return vif;
 458 }
 459
 460 int xenvif_init_queue(struct xenvif_queue *queue)
 461 {
 462         int err, i;
 463
 464         queue->credit_bytes = queue->remaining_credit = ~0UL;
 465         queue->credit_usec  = 0UL;
 466         init_timer(&queue->credit_timeout);
 467         queue->credit_window_start = get_jiffies_64();
 468
 469         queue->rx_queue_max = XENVIF_RX_QUEUE_BYTES;
 470
 471         skb_queue_head_init(&queue->rx_queue);
 472         skb_queue_head_init(&queue->tx_queue);
 473
 474         queue->pending_cons = 0;
 475         queue->pending_prod = MAX_PENDING_REQS;
 476         for (i = 0; i < MAX_PENDING_REQS; ++i)
 477                 queue->pending_ring[i] = i;
 478
 479         spin_lock_init(&queue->callback_lock);
 480         spin_lock_init(&queue->response_lock);
 481
 482         /* If ballooning is disabled, this will consume real memory, so you
 483          * better enable it. The long term solution would be to use just a
 484          * bunch of valid page descriptors, without dependency on ballooning
 485          */
 486         err = alloc_xenballooned_pages(MAX_PENDING_REQS,
 487                                        queue->mmap_pages,
 488                                        false);
 489         if (err) {
 490                 netdev_err(queue->vif->dev, "Could not reserve mmap_pages\n");
 491                 return -ENOMEM;
 492         }
 493
 494         for (i = 0; i < MAX_PENDING_REQS; i++) {
 495                 queue->pending_tx_info[i].callback_struct = (struct ubuf_info)
 496                         { .callback = xenvif_zerocopy_callback,
 497                           .ctx = NULL,
 498                           .desc = i };
 499                 queue->grant_tx_handle[i] = NETBACK_INVALID_HANDLE;
 500         }
 501
 502         return 0;
 503 }
 504
 505 void xenvif_carrier_on(struct xenvif *vif)
 506 {
 507         rtnl_lock();
 508         if (!vif->can_sg && vif->dev->mtu > ETH_DATA_LEN)
 509                 dev_set_mtu(vif->dev, ETH_DATA_LEN);
 510         netdev_update_features(vif->dev);
 511         set_bit(VIF_STATUS_CONNECTED, &vif->status);
 512         if (netif_running(vif->dev))
 513                 xenvif_up(vif);
 514         rtnl_unlock();
 515 }
 516
 517 int xenvif_connect(struct xenvif_queue *queue, unsigned long tx_ring_ref,
 518                    unsigned long rx_ring_ref, unsigned int tx_evtchn,
 519                    unsigned int rx_evtchn)
 520 {
 521         struct task_struct *task;
 522         int err = -ENOMEM;
 523
 524         BUG_ON(queue->tx_irq);
 525         BUG_ON(queue->task);
 526         BUG_ON(queue->dealloc_task);
 527
 528         err = xenvif_map_frontend_rings(queue, tx_ring_ref, rx_ring_ref);
 529         if (err < 0)
 530                 goto err;
 531
 532         init_waitqueue_head(&queue->wq);
 533         init_waitqueue_head(&queue->dealloc_wq);
 534         atomic_set(&queue->inflight_packets, 0);
 535
 536         netif_napi_add(queue->vif->dev, &queue->napi, xenvif_poll,
 537                         XENVIF_NAPI_WEIGHT);
 538
 539         if (tx_evtchn == rx_evtchn) {
 540                 /* feature-split-event-channels == 0 */
 541                 err = bind_interdomain_evtchn_to_irqhandler(
 542                         queue->vif->domid, tx_evtchn, xenvif_interrupt, 0,
 543                         queue->name, queue);
 544                 if (err < 0)
 545                         goto err_unmap;
 546                 queue->tx_irq = queue->rx_irq = err;
 547                 disable_irq(queue->tx_irq);
 548         } else {
 549                 /* feature-split-event-channels == 1 */
 550                 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
 551                          "%s-tx", queue->name);
 552                 err = bind_interdomain_evtchn_to_irqhandler(
 553                         queue->vif->domid, tx_evtchn, xenvif_tx_interrupt, 0,
 554                         queue->tx_irq_name, queue);
 555                 if (err < 0)
 556                         goto err_unmap;
 557                 queue->tx_irq = err;
 558                 disable_irq(queue->tx_irq);
 559
 560                 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
 561                          "%s-rx", queue->name);
 562                 err = bind_interdomain_evtchn_to_irqhandler(
 563                         queue->vif->domid, rx_evtchn, xenvif_rx_interrupt, 0,
 564                         queue->rx_irq_name, queue);
 565                 if (err < 0)
 566                         goto err_tx_unbind;
 567                 queue->rx_irq = err;
 568                 disable_irq(queue->rx_irq);
 569         }
 570
 571         queue->stalled = true;
 572
 573         task = kthread_create(xenvif_kthread_guest_rx,
 574                               (void *)queue, "%s-guest-rx", queue->name);
 575         if (IS_ERR(task)) {
 576                 pr_warn("Could not allocate kthread for %s\n", queue->name);
 577                 err = PTR_ERR(task);
 578                 goto err_rx_unbind;
 579         }
 580         queue->task = task;
 581         get_task_struct(task);
 582
 583         task = kthread_create(xenvif_dealloc_kthread,
 584                               (void *)queue, "%s-dealloc", queue->name);
 585         if (IS_ERR(task)) {
 586                 pr_warn("Could not allocate kthread for %s\n", queue->name);
 587                 err = PTR_ERR(task);
 588                 goto err_rx_unbind;
 589         }
 590         queue->dealloc_task = task;
 591
 592         wake_up_process(queue->task);
 593         wake_up_process(queue->dealloc_task);
 594
 595         return 0;
 596
 597 err_rx_unbind:
 598         unbind_from_irqhandler(queue->rx_irq, queue);
 599         queue->rx_irq = 0;
 600 err_tx_unbind:
 601         unbind_from_irqhandler(queue->tx_irq, queue);
 602         queue->tx_irq = 0;
 603 err_unmap:
 604         xenvif_unmap_frontend_rings(queue);
 605 err:
 606         module_put(THIS_MODULE);
 607         return err;
 608 }
 609
 610 void xenvif_carrier_off(struct xenvif *vif)
 611 {
 612         struct net_device *dev = vif->dev;
 613
 614         rtnl_lock();
 615         if (test_and_clear_bit(VIF_STATUS_CONNECTED, &vif->status)) {
 616                 netif_carrier_off(dev); /* discard queued packets */
 617                 if (netif_running(dev))
 618                         xenvif_down(vif);
 619         }
 620         rtnl_unlock();
 621 }
 622
 623 void xenvif_disconnect(struct xenvif *vif)
 624 {
 625         struct xenvif_queue *queue = NULL;
 626         unsigned int num_queues = vif->num_queues;
 627         unsigned int queue_index;
 628
 629         xenvif_carrier_off(vif);
 630
 631         for (queue_index = 0; queue_index < num_queues; ++queue_index) {
 632                 queue = &vif->queues[queue_index];
 633
 634                 netif_napi_del(&queue->napi);
 635
 636                 if (queue->task) {
 637                         kthread_stop(queue->task);
 638                         put_task_struct(queue->task);
 639                         queue->task = NULL;
 640                 }
 641
 642                 if (queue->dealloc_task) {
 643                         kthread_stop(queue->dealloc_task);
 644                         queue->dealloc_task = NULL;
 645                 }
 646
 647                 if (queue->tx_irq) {
 648                         if (queue->tx_irq == queue->rx_irq)
 649                                 unbind_from_irqhandler(queue->tx_irq, queue);
 650                         else {
 651                                 unbind_from_irqhandler(queue->tx_irq, queue);
 652                                 unbind_from_irqhandler(queue->rx_irq, queue);
 653                         }
 654                         queue->tx_irq = 0;
 655                 }
 656
 657                 xenvif_unmap_frontend_rings(queue);
 658         }
 659 }
 660
 661 /* Reverse the relevant parts of xenvif_init_queue().
 662  * Used for queue teardown from xenvif_free(), and on the
 663  * error handling paths in xenbus.c:connect().
 664  */
 665 void xenvif_deinit_queue(struct xenvif_queue *queue)
 666 {
 667         free_xenballooned_pages(MAX_PENDING_REQS, queue->mmap_pages);
 668 }
 669
 670 void xenvif_free(struct xenvif *vif)
 671 {
 672         struct xenvif_queue *queue = NULL;
 673         unsigned int num_queues = vif->num_queues;
 674         unsigned int queue_index;
 675
 676         unregister_netdev(vif->dev);
 677
 678         for (queue_index = 0; queue_index < num_queues; ++queue_index) {
 679                 queue = &vif->queues[queue_index];
 680                 xenvif_deinit_queue(queue);
 681         }
 682
 683         vfree(vif->queues);
 684         vif->queues = NULL;
 685         vif->num_queues = 0;
 686
 687         free_netdev(vif->dev);
 688
 689         module_put(THIS_MODULE);
 690 }